Re: Crawlspace insulation
Remember that concrete is naturally porous. Without a vapor barrier under the concrete, you will probably have infiltration of moisture and possibly radon gas, so you would need to provide ventilation.
Originally Posted by myzx
A few years ago, as a demonstration and experiment, in cooperation with Washington State University and the EPA's Energy Star program, a local builder built a few houses with sealed crawlspaces. They were built as yours, with a concrete slab in the crawlspace. Vapor barrier was installed under the concrete, there was no ventilation provided, and no insulation was installed under the floor. The result was that it did result in some energy savings, but the added cost of building this way took a long time to pencil out in energy savings.
The "Senior Member" designation under my name doesn't mean I know a lot, it just means I talk a lot.I've been a DIYer since I was 12 (thanks, Dad!). I have read several books on various home improvement topics. I do not have any current code books I can refer to. I was an apprentice plumber for two years.